How do I make an inverted sloping wall?

[Cheezy2]

Hey all,

Please have a look at this picture.

How do I create this? I can create a sloping wall of the appropriate angle etc... however, I need the wall to be upside down (i.e. start from the ceiling and down, not from the floor and up) if that makes sense :/

I can't work out if it's the wall that needs to slope, or the ceiling?!

Thank you,
Matthew

[Puybaret]

Import and use the triangle 3D model taking care to orientate it correctly at the second step of the furniture import wizard.

[Cheezy2]

Wicked - thanks so much!